Light projection device and light projection device for vehicle

Abstract

Provided is a light projection device and a light projection device for vehicle, and the light projection device includes: a light source having light emission portions disposed side by side in a predetermined direction; convex lenses, which focus light irradiated from the light emission portions; an optical scanner having a mirror portion that scans the light passing through the convex lenses, and a drive source swinging the mirror portion; and a projection lens disposed between the convex lenses and the mirror portion, or disposed in a position to which the light scanned from the mirror portion is projected. The convex lenses are disposed side by side in the predetermined direction at intervals so that the light transmitted through and focused by the convex lenses in a stationary state comes close.

What is claimed is: 
     
       1. A light projection device, comprising:
 a light source which has a plurality of light emission portions disposed side by side in a predetermined direction; 
 a plurality of convex lenses arranged in the same number as the plurality of light emission portions, which focus light when the light is irradiated from the plurality of light emission portions; 
 an optical scanner which has a mirror portion that scans the light transmitted through the plurality of convex lenses in a direction in which the plurality of light emission portions is arranged, and a drive source that swings the mirror portion; and 
 a projection lens which is disposed between the plurality of convex lenses and the mirror portion, or disposed in a position to which the light scanned from the mirror portion is projected, 
 wherein the plurality of convex lenses is disposed side by side in a predetermined direction at intervals so that the light which is transmitted through and focused by the plurality of convex lenses in a stationary state comes close, 
 the plurality of convex lenses is disposed so that a size of a focusing width of the light in the direction in which the plurality of light emission portions is disposed side by side is equal to or smaller than a size of the intervals between the plurality of light emission portions adjacent to each other in a position in which the light is incident to the mirror portion or the projection lens. 
 
     
     
       2. The light projection device according to  claim 1 , wherein the plurality of convex lenses adjacent to each other are disposed side by side in the predetermined direction at the intervals which are equal to intervals at which the plurality of light emission portions is disposed side by side in the predetermined direction, or smaller than the intervals at which the plurality of light emission portions are disposed side by side in the predetermined direction. 
     
     
       3. The light projection device according to  claim 2 , wherein the plurality of convex lenses is disposed offset in a direction in which the plurality of convex lenses is arranged from positions facing the plurality of light emission portions. 
     
     
       4. The light projection device according to  claim 2 , wherein the optical scanner comprises a control portion which controls the drive source, and
 the control portion of the optical scanner is configured to control the drive source to set a scan angle during scanning of the mirror portion to be equal to or smaller than a full angle at half maximum, wherein the full angle at half maximum is an angle having a value which is a half of a peak value of a light intensity of the light reflected from the mirror portion in the stationary state. 
 
     
     
       5. The light projection device according to  claim 2 , wherein the plurality of convex lenses is configured that virtual images of the plurality of convex lenses, which pass through a principal point and are formed on an opposite side with the light source therebetween, come close and are disposed side by side. 
     
     
       6. The light projection device according to  claim 2 , wherein an incidence angle of the light from the light source when the mirror portion is in the stationary state is equal to or greater than 35 degrees and equal to or smaller than 45 degrees. 
     
     
       7. The light projection device according to  claim 2 , wherein the projection lens is configured to make the light form images along a direction in which irradiated light is scanned, and condense the light toward a direction perpendicular to the direction in which the irradiated light is scanned. 
     
     
       8. The light projection device according to  claim 1 , wherein the optical scanner comprises a control portion which controls the drive source, and
 the control portion of the optical scanner is configured to control the drive source to set a scan angle during scanning of the mirror portion to be equal to or smaller than a full angle at half maximum, wherein the full angle at half maximum is an angle having a value which is a half of a peak value of a light intensity of the light reflected from the mirror portion in the stationary state. 
 
     
     
       9. The light projection device according to  claim 1 , wherein the plurality of convex lenses is configured that virtual images of the plurality of convex lenses, which pass through a principal point and are formed on an opposite side with the light source therebetween, come close and are disposed side by side. 
     
     
       10. The light projection device according to  claim 1 , wherein an incidence angle of the light from the light source when the mirror portion is in the stationary state is equal to or greater than 35 degrees and equal to or smaller than 45 degrees. 
     
     
       11. The light projection device according to  claim 1 , wherein the projection lens is configured to make the light form images along a direction in which irradiated light is scanned, and condense the light toward a direction perpendicular to the direction in which the irradiated light is scanned. 
     
     
       12. A light projection device for vehicle which is mounted on a vehicle and irradiates light ahead of the vehicle, comprising:
 a light source which has a plurality of light emission portions disposed side by side in a predetermined direction; 
 a plurality of convex lenses arranged in the same number as the plurality of light emission portions, which focus the light when the light is irradiated from the plurality of light emission portions; 
 an optical scanner which has a mirror portion that scans the light passing through the plurality of convex lenses in a direction in which the plurality of light emission portions is arranged, and a drive source that swings the mirror portion; and 
 a projection lens which is disposed between the plurality of convex lenses and the mirror portion, or disposed in a position to which the light scanned from the mirror portion is projected, 
 wherein the plurality of convex lenses is disposed side by side in a predetermined direction at intervals so that the light which is transmitted through and focused by the plurality of convex lenses in a stationary state comes close, 
 the plurality of convex lenses is disposed so that a size of a focusing width of the light in the direction in which the plurality of light emission portions is disposed side by side is equal to or smaller than a size of the intervals between the plurality of light emission portions adjacent to each other in a position in which the light is incident to the mirror portion or the projection lens. 
 
     
     
       13. The light projection device for vehicle according to  claim 12 , wherein
 a full angle at half maximum of the mirror portion is set to be equal to or greater than a value of a product of a full angle at half maximum of each of the plurality of light emission portions and a number of the plurality of light emission portions, wherein the full angle at half maximum of the mirror portion is an angle having a value which is a half of a peak value of a light intensity of the light reflected from the mirror portion when the mirror portion is in the stationary state.